Computation of wave effects using the panel method

1 Preprint Numerical Models in Fluid-Structure Interaction Computation of wave effects using the panel method C.-H. Lee 1 & J. N. Newman 1,2 1 WAMIT Inc., USA (www.wamit.com) 2 Department of Ocean Engineering, MIT, USA 1 Introduction Numerical techniques for the prediction of wave effects have achieved an important role in offshore engineering, comparable to physical experiments. For large structures it is appropriate in most cases to use the linear (or weakly nonlinear) potential theory. This permits us to consider structures of quite general geometrical form, for a broad variety of applications. We restrict our attention here to fixed structures and vessels which are free to move in small unsteady motions. Thus we exclude the seakeeping problem for ships which are underway with substantial forward velocity. The panel method, also known as the boundary integral equation method (BIEM), has been widely used for this purpose. The fundamen- tal basis for this method is a form of Green’s theorem where the velocity potential at any point in the fluid is represented by surface distributions of singularities over the boundary surfaces [1, 2, 3, 4]. Generally this leads to an integral equation which must be solved for the unknown source strength or dipole moment. This procedure was mainly of theoretical interest un- til Hess and Smith [5] developed the panel method and demonstrated its validity for three-dimensional bodies in unbounded fluid domains. The method of Hess and Smith is referred to as the ‘low-order panel method’, to distinguish it from various higher-order extensions. The essen- tial steps in the low-order method can be enumerated as follows: (1) the potential is represented either by a source distribution of unknown strength

Computation of wave effects using the panel method

Documents

finite difference method

hydrodynamic load

velocity

wave effects

offshore engineering